Khayyam is a program for composing 3D scenes for rendering (similar to Poser and DAZ Studio). It can import character and scene models from many model formats (Poser, MD5, BSP, OBJ, 3DS, Collada, and formats used in most Illusion games). There is support for basic object placement, scaling, posing skeletal characters, and lighting. Scenes can be exported in POV-Ray format for rendering. Khayyam is implemented as a shell program using many libraries from the Floyd and Sodipodi projects.

KiCad EDA is software for the creation of
electronic schematic diagrams and printed circuit
board artwork. It is a set of four programs and a
project manager: Eeschema (schematic entry),
Pcbnew (a board editor), Gerbview (a Gerber viewer
(photoplotter documents)), and Cvpcb (a footprint
selector for components used in the circuit
design). Kicad is the project manager. It includes
a 3D visualization feature.

Kid3 tagger can edit the ID3v1 tags and all ID3v2
frames in MP3 files and the tags in Ogg/Vorbis and
FLAC files in an efficient way. It is easy to
convert between ID3v1 and ID3v2, set the tags of
multiple files to the same values and generate the
tags from the file name or vice versa. Import is
possible from freedb.org, MusicBrainz, and other
sources of track data.

KildClient is a MUD client written with the GTK+
windowing toolkit. It supports many common
features of other clients, such as triggers, gags,
aliases, macros, timers, and much more. But its
main feature is the built-in Perl interpreter. At
any moment, the user can execute Perl statements
and functions to do things much more powerful than
simply sending text the the MUD. Perl statements
can also be run, for example, as the action of a
trigger, allowing you to do complex things.

Kimai is software that tracks work time and
classifies it. It tracks time and prints out a
summary (time sheet) of your activities on demand.
The reports can be yearly, monthly, daily, by
customer, by project, or by action. Its interface
is based on using a Web browser. You can install
it as a Web service or as a single-user program on
your local workstation. It is appropriate both for
multiple simultaneous users or a single user.
Kimai does not have to run to do the recording.

KinderGate Parental Control features content filtering based on morphological analysis, a vast URL database divided into 70+ categories, download control, safe search, HTTPS support, and more. It provides high accuracy Web filtering with an extremely low false detection rate. It blocks resources related to malware, porn, drugs, abusive content, illegal materials, and other categories. It is widely used by schools, libraries, and home users.

Kinonk is a Pentominoes program written in C++.
Pentominoes is a two-player board game where the
goal is to be the last player to put a pentomino
(a piece composed of five squares) on the board.
Kinonk can also play Katamino, a variant of
pentominoes. It uses a simple brute force
algorithm, and can play any position perfectly if
given enough time. You can constrain its time by
giving an arbitrary time limit, or simply let it
analyze everything. Charts can be generated using
a Perl script included in the package.